Marzocchi Pompe was founded in 1961 by Guglielmo and Stefano Marzocchi, in Casalecchio di Reno, in the outskirts of Bologna. Today, Marzocchi Pompe leads an industrial group – the Marzocchi Group - that employs more than 400 people. The Group, owned and directed by Adriano and Paolo Marzocchi, works in the hydraulic pump and motor sectors and in the suspension systems for motorcycles and mountain bikes. Marzocchi Pompe developed in time both their dimensions and their product range, being at present among the major manufacturers of external gear hydraulic pumps and motors. Marzocchi Pompe is now the most reliable partner, making available to the customer their specific know-how, high quality and a perfect service for all hydraulic applications, thanks to the fame and experience achieved over many years.

GENERAL INFORMATIONBASIC DESIGN External gear pumps are the most popular pumps used in modern hydraulic systems. They feature versatility, strength and long useful life. Their simple construction ensures limited purchase costs and servicing. Thanks to these basic concepts, together with ever-improving product design and features, research-based on many years of experience, accuracy in material selection, production process followed in great detail and tests on mass-produced parts, our gear pumps have reached top quality standards. For this reason, our products can work under heavy operating conditions and transmit high hydraulic power. Furthermore, Marzocchi pumps feature good hydraulic, mechanical and volumetric efficiency, low noise level and, last but not least, compact dimensions and low weight/power ratio. Marzocchi Pompe thus specialized their production in low - power oil - operated pumps for auxiliary services. This product is called 1P and it is widely used in power units. A 1P gear pump usually consists of a gear pair supported by two aluminum bushes, a body, a securing flange and a cover. Shaft of the driving gear projecting beyond the flange mounts a twin - lip seal ring (the inner lip being a seal and the outer being a dust seal). An elastic securing ring secures the ring in place. Pump body, flange and cover are made of special hi-resistant aluminum alloys for minimized deformation even when subject to high pressure, be it continuous or intermittent or peak pressure. The body is profiled by means of extrusion, whereas flange and cover are obtained by means of die-casting. Gears are made of special steel. Their manufacturing process includes case-hardening and quench hardening. Then gears are ground and fine finished so to have a high degree of surface finishing. Proper tooth profile design and geometric proportions ensure low pulsation levels and low noise levels during pump operation. Bushes are made of special low - friction and hi-resistant aluminum alloy and manufactured from die - casting. Special compensation zones onto flange and cover, insulated by special seals with anti - extrusion ring, allow fully free axial and radial movement to the bushes, which is proportional to pump operating pressure. In this way, internal dripping is dramatically reduced, thus ensuring very good pump performance (both in terms of volume and in general) and proper lubrication of pump moving parts.

PRODUCT RANGE 1P Marzocchi gear pumps are available in different displacements that can be obtained by changing the thickness of the gear toothed band. Different flanges, shafts, inlet and pressure ports are available. The following items are also available: - bi-rotational pumps; - pumps with pressure limiting valve; - double pumps.

SPECIAL VERSIONS The following 1P models for special uses are available: “V” - Version suitable for fluid hi-temperature applications. Range between -10°C and +120°C with P1, P2 and P3 as per product table, up to +80°C; do not go over P1 for higher temperatures. Range until +150°C with max. pressure = 20 bar (please indicate actual values when ordering). “ST” - Version suitable for fluid at hi- or low-temperature applications. Range between -40°C and +120°C. “TR” - Version suitable for inlet pressure up to max. 6 bar absolute.

Please call our Technical and Sales Depts. for your application requirements and any special use not included in this catalogue.

TECHNICAL INFORMATIONPlease strictly follow assembly and use indications given in this catalogue for top performance and longer life of Marzocchi products. Some general considerations should be made on the hydraulic system, in which the pump must be fitted. Special attention shall be devoted to hydraulic system design and assembly, especially to intake, delivery and return pipes and position of system parts (valves, filters, tanks, heat exchangers and accumulators). Proper safety devices and reliable instruments to avoid fluid turbulence, especially in return pipe to the tank, and prevent air, water or foreign bodies from entering into the system are of major importance. It is also very important to equip the hydraulic system with a proper filtering unit.

INSTALLATION NOTES Before starting the system on a continuous basis, we suggest to adopt some simple precautions. - Check for the direction of rotation of the pump to be consistent with the drive shaft one (in case of single rotation pump). - Check for the proper alignment of pump shaft and motor shaft: it is necessary that the connection does not induce axial or radial loads. - Protect drive shaft seal during pump painting. Check if contact area between seal ring and shaft is clean: dust could provoke quicker wear and leakage. - Remove all dirt, chips and all foreign bodies from flanges connecting inlet and delivery ports. - Ensure that intake and return pipes ends are always below fluid level and as far from each other as possible. - Install the pump below head, if possible. - Fill the pump with fluid, and turn it by hand. - Disconnect pump drain during startup to bleed air off the circuit. - At first startup, set pressure limiting valves at min. value possible. - Avoid lower rotation speed than min. allowed with pressure higher than P1. - Do not start the system at low temperatures under load conditions or after long stops (always avoid or limit load starting for pump longer life); - Start the system for a few minutes and turn on all components; bleed air off the circuit to check its proper filling. - Check fluid level in the tank after loading all components. - At last, gradually increase pressure, continuously check fluid and moving parts temperature, check rotation speed until you reach set operating values that shall be within the limits indicated in this catalogue.

CLEANING AND FILTERING THE SYSTEM It is widely known that most pumps early failures are due to contaminated fluids. The extreme reduction of the tolerances for the small parts fitted onto pumps and the following operation with minimum clearance, could be damaged if fluid is not perfectly clean. It is proved that particles circulating in the fluid act as abrasive agents, damaging the surfaces they touch and increasing the quantity of contaminant. For this reason, ensure that system is perfectly clean during startup and keep it clean for its whole operating life. Necessary interventions to check and limit contamination should be performed in a preventive and corrective way. Preventive actions include: proper cleaning of the system during assembly, deburring, eliminating the welding scum and fluid filtering before filling up. Starting contamination level of system fluid should not exceed class 18/15 (ref. ISO 4406). Even fresh fluids might exceed this contamination level; therefore always pre - filter the fluid when filling up or topping up the system. Fit a proper tank; its capacity should be at least twice the flow rate per working minute. Fluid contamination level check and correction during operation can be obtained through filters that retain the particles in the fluid. Two parameters tell which filter is most suitable: absolute filtering power and β filtering ratio. Low absolute filtering power and high β filtering ratio for small particles help ensuring good filtration. It is then very important to limit not only max. dimensions, but also the number of smaller particles that pass through the filter. It goes without saying that with an operating pressure increase and according to the system sophistication degree, filtering should become more and more efficient. The filtering system shall always ensure contamination levels not exceeding the values indicated below:

If fluids other than the above mentioned ones are used, please always indicate type of used fluid and operating conditions so that our Sales and Technical Dept. can weigh possible problems on compatibility or useful life of system parts.

INLET PRESSURE Under standard working conditions, intake pipe pressure is lower than atmospheric pressure, therefore operating pressure should range between the following values: Max. 3,0 bar (assoluti/absolute) In case the pump must work with higher pressure in the intake pipe, a special “TR” version is available. Please call our Technical and Sales Dept. for values other than values indicated.

MIN. ROTATION SPEED Marzocchi 1P pump versatility can be perceived from the wide range of rotation speeds they can be subject to: max. values are indicated in product tables and change according to the model, while min. values are as follows:

INLET AND DELIVERY LINES Hydraulic system pipes should show no sudden changes of direction, sharp bends and sudden differences in cross-section. They should not be too long or out of proportion. Pipe cross-section should be sized so that fluid velocity does not exceed recommended values. It is advisable to carefully consider the possible diameter reduction of the inlet or outlet pipes fitted on flange fittings.

DIRECTION OF ROTATION Marzocchi 1P pumps are available in both single rotation and bi-rotational configurations. Direction of rotation of single rotation pumps is conventionally defined as follows: when standing before the pump with driving shaft up with its projecting end towards the observer, the pump is rotating clockwise in case of right - hand rotation "D"; therefore, delivery side is on the right, whereas intake side is on the left. The contrary will happen with left - hand pumps "S", keeping the same point of view.

DRIVE Connect the pump to the motor using either a flexible coupling (either box or Holdham coupling) so that no radial and/or axial force is transmitted to the pump shaft during rotation, otherwise pump efficiency will dramatically drop due to early wear of inner moving parts. Therefore, coupling must absorb inevitable - even though reduced - misalignment between pump shaft and motor shaft. Box coupling or Holdham coupling should also move axially freely enough (enough for proper contact surface onto pump driving shaft). Furthermore, to avoid early wear of either splined or Holdham couplings, they should be lubricated at regular intervals using specific grease.

FREQUENTLY USED FORMULAS Some frequently used formulas for calculating important parameters are given below. Fluid velocity Calculate the velocity (v) of a fluid in a pipe as follows: v=Q/6 Q A = flow rate [liter/min] = inside area of pipe [cm2]

Note Values for hvol and hhm (and consequently htot) depend on pressure differential between inlet and delivery, rotation speed, fluid features (temperature and viscosity) and filtering degree. Call our Sales and Technical Dept. for further details on efficiency. The proper values for flow rate, torque and power absorbed according to pressure differential, rotation speed and set test conditions, can be found in diagram on pages 21-24.

MONODIRECTIONAL 1P SINGLE PUMPSThis chapter describes Marzocchi external single gear 1P pumps, their operating features and how to select the right pump for the required application. 1P pumps are small hydraulic machines converting mechanical power into hydraulic power. This section deals with rotary positivedisplacement pumps. In this type of pump, a given volume of fluid flows from inlet to outlet at each shaft rotation (theoretical displacement). Pressure depends on delivery line resistance to fluid flow. As gear pumps only transfer fluid, they are subject to pressure generated by the circuit. Therefore, if system flow rate and motor rotation speed are known, it is easy to select the right pump displacement and its model. The diagram indicating flow rate variations according to speed and pressure, shows that not all the theoretically available fluid is transferred from inlet to outlet because of pump internal dripping. Dripping can be remarkably reduced through pressure axial compensating systems (as described at the beginning of this catalogue) but never eliminated. Dripping increases as circuit pressure increases. A pump requires power, even if a limited quantity, just like any other hydraulic machine. Part of this power is given to the fluid to increase pressure required by the circuit, the remaining part is used to win pump internal friction. Therefore, for proper pump operation, supplied torque shall be higher than theoretical torque. The following diagrams show, for each single displacement, the typical required power as a function of rotation speed and pressure generated by the system and allow you to easily spot the product suitable for your application. Once the pump flow rate has been selected, different flanges, shafts, inlet and outlet port position and type are available to meet our Customer’s needs. In the cover of 1P VM model is located a pressure limiting valve that reduces system pressure to a set value to avoid overloads. Valve conformation ensures optimum operation (seal and prompt reaction) only for limited intervention in time, mainly for “DI” inner drain system versions and for high flow rates. Flow rate values at 1500 rotation per minute shown in product tables are theoretical values. All photographs and drawings show clockwise rotation pumps except 1P BW model (page 19) shown with counterclockwise rotation. The inlet and outlet ports in a counterclockwise rotating pump are in the opposite position compared to a clockwise pump.

Standard ports: M6 thread depth 12 mm. “DI”: flow discharged by the valve returns to the inlet area. In case of anticlockwise rotation, both cover and valve rotate of 180°. The valve can be supplied with an operating pressure setting chosen in a range from 10 up to 280 bar. VM model is also available for KL1P, KF1P, 1BK4 and 1BK7 pumps. OPTIONS Upon request, 1P VM is also available in “GAS” version. “DE” flow discharged by the valve is drained to an external G1/4 port thread depth 10 mm.ASPIRAZIONE INLET

SINGLE 1P BI-ROTATIONAL PUMPSAs described at the beginning of the single rotation pump section, also bi-rotational models are rotary positive-displacement pumps with external gears. Their operating concept is the same as single rotation pumps. What changes is that bi-rotational pumps can rotate both clockwise and counterclockwise thanks to their perfectly symmetrical machining on the internal components. Some models have the external drain positioned on the flange or on the cover; connection pipes to the system tank should never be clogged or show reduced cross-section, otherwise pressure values might exceed 6 bar. The reversible 1P pump is capable of handling pressurized inflow. Please call our Sales and Technical Dept. if system operating conditions differ from the values indicated in the product tables.

DOUBLE 1P PUMPS1P pumps are available in double version, too. Please contact our Sales-Technical Dept. for further details on specific configurations not explicitly indicated (flanges, shafts and so on). For proper operation of Marzocchi 1P double pumps, you shall comply with the following instructions: - check that power absorption of the front element is equal or higher than the rear element. - element performance and features are the same as the elements of the corresponding single pumps. - Double pump max. rotation speed is determined by the lowest speed among max. rotation speeds of every single element. - Operating pressures are limited by the max. torque transmissible by the shaft of the first element and by the shaft connecting the two elements one to the other. - the torque transmitted by the shaft of the first element is the sum of the torques transmitted by each single element. The torque of every single element can be determined with the following formula. Absorbed torque Calculate necessary torque (M) of a pump subject to pressure differential between inlet and outlet as follows: M = (V D p) / (62.8 ηhm) [Nm] = displacement [cm3/rotation] D p = pressure differential [bar] ηhm = hydromechanical efficiency (take 0.80 as indicative value under cold conditions and 0.85 under working conditions). V

Driving shaft absorbed torque For a proper check of the shafts and of the max. torques that they can bear, see the following example. Primary shaft check Let’s say that we should use a double pump 1P D 9.2 + 1P D 4.2 with max. pressure respectively of 150 bar and 100 bar. By making pressure values correspond to the sizes in the table on the side, we shall obtain as a result the following: 1P D 9.2 element can bear 14.8 Nm and 1P D 4.2 element can bear 4.5 Nm. You then have that the torque applied on the shaft of the first element will be the sum of the torques absorbed by the two pumps: 14.8 + 4.5 = 19.3 Nm This value shall never go over the limit value allowed for that type of shaft (in this case, max. value would be 26.3 Nm). Secondary shaft check In our example the torque applied to the shaft of the second element (4.2 Nm) is allowed because it does not exceed the limit for that type of shaft (in this case, max. value would be 21.5 Nm).

FITTINGS Fittings are available in aluminum for RG type and in iron for RFI and RDFI types; they are supplied with screws (socket cheese-headed screws, strength class 8.8), spring washers and gaskets (in elastomer Buna - N, hardness: 70 Shore A) for assembly. We can supply galvanized white or yellow screws, on demand.

Marzocchi Pompe cannot be held liable for possible mistakes made while editing this catalogue. Without considering general features, installation instructions and use instructions, data indicated in this publication are supplied for your information. We reserve ourselves the right to change the technical specification of our products without prior communication. Pumps and motor special applications requiring high reliability factor during operation (e.g. aeronautical, aerospace, air force, nuclear equipment, and so on) shall be mentioned on the order and shall receive our written approval.